<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var num1=prompt("请输入第一数：");


  var num2=prompt("请输入第2数：");


var   s=prompt("请输入运算符：+-*/");
function   jisuna(num1,num2){
    if(s=="+"){
        num= parseInt(num1) + parseInt(num2);
        alert(num);

    }else if(s=="-"){
        num=parseInt(num1) -parseInt(num2);
        alert(num);
    }else if(s=="*"){
        num=parseInt(num1) * parseInt(num2);
        alert(num);
    }else if(s=="/"){
        num=parseInt(num1)/parseInt(num2);
        alert(num);
    }



}

jisuna(num1,num2);

    </script>
    
</body>
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